This demonstration shows that similar-appearing lights can be distinctly different, suggesting that the light emitted is generated in different ways. It requires some advance preparation/setup by the teacher and three recommended sources of orange...(View More) light, that can be purchased at a hardware or department store. Includes extensions and additional background information on light generation in a section on underlying principles. This resource is from PUMAS - Practical Uses of Math and Science - a collection of brief examples created by scientists and engineers showing how math and science topics taught in K-12 classes have real world applications.(View Less)